JP2021081554A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that attaches, to a drawer, a process cartridge including a drum cartridge having a photoconductor drum and a developing cartridge having a toner storage unit and a developing roller, and a novel configuration that further facilitates an operation to replace only the developing cartridge.SOLUTION: A first developing cartridge 52-1 is movable, in a state where it is attached to a first drum cartridge 51-1, between a first position where it is removably attached to the first drum cartridge 51-1 and a second position where a first developing roller 55-1 is supported at a position where it can supply a toner to a first photoconductor drum 54-1. When the first developing cartridge 52-1 is moved from the second position toward the first position in a state where it is attached to a drawer 80, the first developing cartridge 52-1 and the second process cartridge 50-2 interfere with each other before the first developing cartridge 52-1 reaches the first position, and the first developing cartridge 52-1 does not reach the first position.SELECTED DRAWING: Figure 19

Description

The present invention relates to an image forming apparatus.

In an electrophotographic image forming apparatus such as a laser printer, an image forming apparatus is known in which a drum cartridge having a photosensitive drum and a process cartridge including a toner accommodating portion and a developing cartridge having a developing roller are mounted on a drawer ( See Patent Document 1 and Patent Document 2).

JP-A-2017-102150 Japanese Unexamined Patent Publication No. 2010-224061

When replacing only the developing cartridge in the configurations of Patent Document 1 and Patent Document 2, "a method of replacing the developing cartridge with the process cartridge attached to the drawer" and "a method of replacing the developing cartridge after removing the process cartridge from the drawer" and "the developing cartridge". How to replace ". At this time, it is better to remove the process cartridge from the drawer and then replace the developing cartridge because the work space can be widened.

However, in the configurations of Patent Document 1 and Patent Document 2, although it is possible to remove the process cartridge from the drawer and then replace the developing cartridge, the configuration is considered so that the work can be easily performed. There wasn't.

According to the present invention, in an image forming apparatus in which a drum cartridge having a photosensitive drum and a process cartridge including a toner accommodating portion and a developing cartridge having a developing roller are mounted on a drawer, when it is desired to replace only the developing cartridge, the replacement work can be performed. The purpose is to provide a new configuration that can be made easier.

The image forming apparatus of the present invention moves between a housing having an opening, an inner position housed in the housing, and an outer position partially exposed to the outside of the housing through the opening. A first drum cartridge having a possible drawer, a first process cartridge that can be attached to and detached from the drawer, a first photosensitive drum, and a first drum frame that supports the first photosensitive drum, and the first photosensitive drum. A first developing cartridge that has a first developing roller that supplies toner to a drum, a first developing frame that supports the first developing roller and can accommodate the toner, and is removable from the first drum cartridge. A first process cartridge comprising the above, and a second process cartridge that is attached to and detached from the drawer adjacent to the first process cartridge. When the first developing cartridge is mounted on the first drum cartridge, the first developing cartridge is in a position where it can be attached to and detached from the first drum cartridge, and the first developing roller puts toner on the first photosensitive drum. It is movable to and from a second position supported by a supplyable position. With the first process cartridge mounted and positioned at the second position and the second process cartridge mounted on the drawer, the first developing cartridge is mounted from the second position to the first. When the first development cartridge is moved toward the position, the first development cartridge interferes with the second process cartridge before the first development cartridge reaches the first position, and the first development cartridge is the first. Does not reach the position.

According to the above configuration, the "method of replacing the developing cartridge with the process cartridge attached to the drawer" makes it impossible to replace the developing cartridge, thereby ensuring that the user "removes the process cartridge from the drawer". Then you can lead to "How to replace the developing cartridge". In other words, the user will not be confused as to which of "the method of replacing the developing cartridge with the process cartridge attached to the drawer" and "the method of removing the process cartridge from the drawer and then replacing the developing cartridge" is the correct operation. ..

Further, when the first development cartridge is moved from the second position to the first position with the first process cartridge and the second process cartridge equipped with the first development cartridge mounted on the drawer, the first development cartridge is used. Since the distance between the first process cartridge and the second process cartridge is so narrow that the image forming apparatus interferes with the second process cartridge, the entire image forming apparatus can be miniaturized.

In the above configuration, when the first developing cartridge is mounted on the first drum cartridge, the first developing cartridge is located between the first position and the second position with the rotation axis of the first developing roller as the center. It may be rotated.

According to the above configuration, when the first developing cartridge rotates between the first position and the second position, the first developing roller and the first photosensitive drum may rub against each other and be damaged due to the rotation. The sex can be reduced.

Further, in the above configuration, the first drum cartridge has a lock position that prevents the first development cartridge from rotating from the second position to the first position, and the first development cartridge from the second position. It may have a first lock member that can move to and from an unlocked position that allows rotation to the first position.

According to the above configuration, it is possible to prevent the first developing cartridge from being unintentionally detached from the first drum cartridge.

Further, in the above configuration, the first locking member has a first operating portion and a first engaging portion that engages with the first developing cartridge, the drawer is in the outer position, and the first In a state where the process cartridge and the second process cartridge are supported by the drawer and the first lock member is in the locked position, the first operation unit is sandwiched between the first process cartridge and the second process cartridge. It may be arranged in the above-mentioned position.

According to the above configuration, when the first process cartridge is mounted on the drawer, it becomes difficult to operate the first operation unit, and it is possible to prevent the first lock member from being unlocked.

Further, in the above configuration, in a state where the drawer is in the outer position and the first process cartridge is supported by the drawer, the first operation unit in the unlocked position is the first operating unit in the locked position. 1 It may be located above the operation unit.

Further, in the above configuration, the first drum frame has a first side frame and a second side frame, and in a state where the first development cartridge is mounted on the first drum cartridge, the first development The cartridge may be rotatably supported between the first side frame and the second side frame between the first position and the second position.

Further, in the above configuration, the first drum frame has an upper frame connecting the first side frame and the second side frame, and the first developing cartridge is mounted on the first drum cartridge and said to be the first. In the state of being in two positions, it is housed in a space sandwiched between the first photosensitive drum and the upper frame, the drawer is in the outer position, the first process cartridge is supported by the drawer, and the first developing cartridge is supported. May be attached to the first drum cartridge and in the second position, the upper frame of the first drum frame may cover at least a part of the upper surface of the first developing cartridge.

According to the above configuration, at least on the upper surface of the first developing cartridge in a state where the drawer is in the outer position, the first process cartridge is supported by the drawer, the first developing cartridge is mounted on the first drum cartridge and is in the second position. Since a part of the drum frame is covered and hidden by the upper frame, it becomes difficult for the user to grasp the first developing cartridge. As a result, the user can be more reliably guided to "a method of removing the process cartridge from the drawer and then replacing the developing cartridge".

Further, in the above configuration, the first drum frame has a front frame connecting the first side frame and the second side frame, and the first developing cartridge is mounted on the first drum cartridge and the second drum frame is attached. In the position, the first developing cartridge is housed in a space surrounded by the first side frame, the second side frame, and the front frame, and the first process cartridge is placed in the space surrounded by the first developing cartridge. When the front frame is placed in a downward position while being mounted on the first drum cartridge and the first developing cartridge is rotated from the second position to the first position, the first developing cartridge is said to be the same. It may be rotated in a direction away from the front frame.

According to the above configuration, it is possible to easily attach / detach the first developing cartridge with the first process cartridge placed on the work table with the front frame facing down.

Further, in the above configuration, when the first process cartridge is placed in a posture in which the front frame faces downward with the first development cartridge mounted on the first drum cartridge, the first operation unit is said to be the same. It is located above the first engaging portion, and when the first operating portion is pushed down, the first locking member may move from the locking position to the unlocking position.

According to the above configuration, the first lock member can be moved to the unlocked position simply by pushing down the first operation unit, so that the lock of the first lock member can be easily released.

According to the present invention, in an image forming apparatus in which a drum cartridge having a photosensitive drum and a process cartridge including a toner accommodating portion and a developing cartridge having a developing roller are mounted on a drawer, when it is desired to replace only the developing cartridge, the replacement thereof. It is possible to provide a new configuration that makes the work easier.

For details, "How to replace the developing cartridge with the process cartridge attached to the drawer" makes it impossible to replace the developing cartridge, thereby ensuring that the user "removes the process cartridge from the drawer and then replaces the developing cartridge." Can lead to "how to replace". In other words, the user will not be confused as to which of "the method of replacing the developing cartridge with the process cartridge attached to the drawer" and "the method of removing the process cartridge from the drawer and then replacing the developing cartridge" is the correct operation. ..

Further, when the first development cartridge is moved from the second position to the first position with the first process cartridge and the second process cartridge equipped with the first development cartridge mounted on the drawer, the first development cartridge is used. Since the distance between the first process cartridge and the second process cartridge is so narrow that the image forming apparatus interferes with the second process cartridge, the entire image forming apparatus can be miniaturized.

It is a side sectional view of the image forming apparatus of one Embodiment. It is a perspective view of a developing cartridge. It is a front view of a developing cartridge. It is a right side view of a developing cartridge. It is sectional drawing BB of the development cartridge of FIG. 3, (a) shows the state which the reception shutter is closed, and (b) shows the state which the reception shutter is open. It is a perspective view of a drum cartridge. It is a rear sectional view of the drum cartridge cut at the position AA of FIG. FIG. 7 is a cross-sectional view taken along the line CC of FIG. FIG. 7 is a cross-sectional view taken along the line DD of FIG. FIG. 7 is a cross-sectional view taken along the line EE of FIG. It is a side cross section of a drum cartridge in a state of being placed on a horizontal plane, and is a figure explaining a state in which a developing cartridge is in a second position. It is a side cross section of a drum cartridge in a state of being placed on a horizontal plane, and is a figure explaining a state in which a lock member is in an unlocked position. It is a side cross section of a process cartridge in a state of being placed on a horizontal plane, and is a figure explaining a state in which a developing cartridge is in a second position. It is a side cross section of a process cartridge in a state of being placed on a horizontal plane, and is a figure explaining a state in which a developing cartridge is in a first position. It is a rear sectional view of the image forming apparatus cut at the position AA of FIG. It is a side sectional view of the image forming apparatus cut at the FF position of FIG. FIG. 16 is a diagram showing a state in which the front cover is in the open position in FIG. FIG. 16 is a diagram showing a state in which the drawer is in the outer position in FIG. It is a side sectional view which shows the 4th process carridge from the 1st process carridge attached to the drawer which is in the outer position.

[Overall configuration of image forming apparatus]
The image forming apparatus 1 shown in FIG. 1 is an embodiment of the image forming apparatus according to the present invention, and is an electrophotographic tandem color printer that forms an image of a plurality of colors on paper S.

In the following description, the left side in FIG. 1 is defined as the rear side of the image forming apparatus 1, the right side in FIG. 1 is defined as the front side of the image forming apparatus 1, and the front side of the paper surface in FIG. 1 is the left side of the image forming apparatus 1, in FIG. The back side of the paper surface is defined as the right side of the image forming apparatus 1. Further, the upper side and the lower side in FIG. 1 are defined as the upper side and the lower side of the image forming apparatus 1, respectively.

The image forming apparatus 1 includes a housing 2 constituting the main body of the apparatus, a paper feed tray 10 for supporting the paper S, and an image forming unit 5 for forming an image on the paper S.

The housing 2 is formed in a substantially rectangular parallelepiped shape, and houses the paper feed tray 10 and the image forming unit 5. An opening 2A is formed on the front surface 21 of the housing 2. The housing 2 has a front cover 22 capable of opening and closing the opening 2A.

The front cover 22 is configured to be rotatable around a rotation shaft 22A at the lower end. The front cover 22 is rotatable between a closed position that covers the opening 2A (the position shown in FIG. 1) and an open position that opens the opening 2A (the position shown in FIG. 17). A paper ejection tray 23A that inclines downward from the front side to the rear side is formed on the upper surface 23 of the housing 2.

Inside the housing 2, a transport path P for the paper S from the paper feed tray 10 to the paper output tray 23A via the image forming unit 5 is configured. A paper feed roller 11, a separation roller 12, and a separation pad 12A are provided in the housing 2. The paper S supported by the paper feed tray 10 is separated one by one by the paper feed roller 11, the separation roller 12, and the separation pad 12A, and is sent out to the transport path P. The paper S sent out to the transport path P is transported toward the image forming unit 5.

The image forming unit 5 is arranged above the paper feed tray 10, and includes four process cartridges 50 arranged side by side in the front-rear direction. Each process cartridge 50 is detachably attached to the housing 2 and is provided corresponding to each color of black, yellow, magenta, and cyan, respectively.

The housing 2 has a drawer 80, and the process cartridge 50 is supported by the drawer 80. The process cartridge 50 has a drum cartridge 51 and a developing cartridge 52. The drum cartridge 51 is detachably attached to the drawer 80, and the developing cartridge 52 is detachably attached to the drum cartridge 51.

The drum cartridge 51 includes a photosensitive drum 54, a charging roller 58, and a drum cleaner 59. The photosensitive drum 54 is formed in a substantially cylindrical shape with the left-right direction as the axial direction, and is rotatably supported by the drum cartridge 51. The charging roller 58 extends in the left-right direction and is in contact with the rear upper portion of the photosensitive drum 54. The drum cleaner 59 has a cleaning blade 591 (see FIG. 8) that comes into contact with the surface of the photosensitive drum 54. The cleaning blade 591 is formed in a flat plate shape with the left-right direction as the longitudinal direction, and its front lower end portion is in contact with the rear portion of the photosensitive drum 54.

The developing cartridge 52 includes a developing roller 55, a supply roller 56, a toner accommodating portion 57 for accommodating toner, and a layer thickness regulating blade 53. The developing roller 55 extends in the left-right direction and is provided so as to be exposed from the lower rear portion to the lower rear portion of the developing cartridge 52. The developing roller 55 is in contact with the front upper portion of the photosensitive drum 54. The supply roller 56 extends in the left-right direction and is in contact with the front upper portion of the developing roller 55. The toner accommodating portion 57 is arranged above the supply roller 56. The layer thickness regulating blade 53 is arranged so as to be in contact with the surface of the developing roller 55.

Toner is supplied to the supply roller 56 from the toner accommodating portion 57, and the supply roller 56 supplies toner to the developing roller 55. At this time, the toner in the toner accommodating portion 57 flows around the supply roller 56 due to gravity and accumulates. Therefore, even if there is no mechanism in the toner accommodating portion 57 for conveying the toner around the supply roller 56, the toner can be conveyed around the supply roller 56 by using gravity. The layer thickness regulating blade 53 adjusts the toner layer on the surface of the developing roller 55 to a predetermined thickness by contacting the surface of the rotating developing roller 55. The developing roller 55 supplies toner to the photosensitive drum 54.

In this way, the developing cartridge 52 having the developing roller 55 can be attached to and detached from the drum cartridge 51 having the photosensitive drum 54, so that the photosensitive drum 54 and the developing roller 55 can be exchanged separately.

Above the process cartridge 50, an exposure unit 60 for exposing the surface of the photosensitive drum 54 is provided.

A belt 31 is arranged to face each other below the transport path P of the photosensitive drum 54. The belt 31 is hung between the drive roller 32 and the driven roller 33 arranged in front of the drive roller 32. Transfer rollers 34 are arranged at positions facing each photosensitive drum 54 with the belt 31 interposed therebetween. The belt unit 30 is composed of a belt 31, a drive roller 32, a driven roller 33, and a transfer roller 34.

In the image forming unit 5, the surface of the photosensitive drum 54 is charged by the charging roller 58 and then selectively exposed by the exposure unit 60 based on predetermined image data. As a result, an electrostatic latent image based on the image data is formed on the surface of the photosensitive drum 54.

On the other hand, the toner contained in the toner accommodating portion 57 is charged between the supply roller 56 and the developing roller 55 and is supported on the surface of the developing roller 55. Then, the toner supported on the developing roller 55 is supplied to the electrostatic latent image on the surface of the photosensitive drum 54, so that the toner image is supported on the surface of the photosensitive drum 54.

When the paper S conveyed toward the image forming unit 5 reaches the belt 31, it is conveyed by the belt 31 and sequentially passes between the belt 31 and each photosensitive drum 54. Then, the toner image on the surface of the photosensitive drum 54 is transferred to the paper S by the transfer bias applied to the transfer roller 34 when facing the paper S. In this way, the toner image carried by the photosensitive drum 54 is transferred to the paper S by the belt unit 30.

At this time, toner that has not been transferred to the paper S may remain on the surface of the photosensitive drum 54. The residual toner remaining on the surface of the photosensitive drum 54 is scraped off from the surface of the photosensitive drum 54 by the cleaning blade 591 of the drum cleaner 59 as the photosensitive drum 54 rotates. As a result, the residual toner remaining on the surface of the photosensitive drum 54 is collected by the drum cleaner 59.

The belt 31 in the present embodiment is configured as a transport belt that conveys the paper S on which the toner image is transferred, but the toner image is transferred to the belt itself, and the toner image transferred to the belt is further transferred to the paper S. It is also possible to construct an intermediate transfer belt that is transferred to the toner.

The paper S on which the toner image is transferred is conveyed to the fixing device 16 arranged downstream of the image forming unit 5. The fixing device 16 includes a heating roller 17 and a pressure roller 18 that presses against the heating roller 17, and the paper S conveyed to the fixing device 16 passes between the heating roller 17 and the pressure roller 18. The toner image is heat-fixed.

The paper S on which the toner image is heat-fixed is conveyed downstream from the fixing device 16 in the conveying direction, further conveyed by the paper ejection roller 19, and ejected to the output tray 23A.

[Development cartridge]
As shown in FIGS. 2 to 5, the developing cartridge 52 has a developing frame 521 that rotatably supports the developing roller 55. The developing roller 55 has a roller shaft 55A, and the roller shaft 55A is supported by the developing frame 521. A toner accommodating portion 57 is formed inside the developing frame 521.

At the upper end of the developing frame 521, a handle 521A that the user can grip when removing the developing cartridge 52 from the drum cartridge 51 is formed. The handle 521A is arranged at the rear end of the developing frame 521 in the front-rear direction in which the drum cartridge 51 is mounted on the drawer 80 and the developing cartridge 52 is mounted on the drum cartridge 51.

The developing frame 521 is formed with a residual toner accommodating portion 522 for accommodating the residual toner collected by the drum cleaner 59 from the surface of the photosensitive drum 54. The residual toner accommodating portion 522 is located in the upper front portion of the toner accommodating portion 57.

A receiving port 522A for receiving the residual toner inside the residual toner accommodating portion 522 is formed on the upper surface of the residual toner accommodating portion 522. The developing cartridge 52 has a reception shutter 523 that can open and close the reception 522A. The receiving inlet shutter 523 is arranged above the residual toner accommodating portion 522.

The inlet / outlet shutter 523 is configured to be movable in the front-rear direction, and the inlet / outlet closing position (position shown in FIG. 5A) for closing the inlet / outlet 522A by moving in the anteroposterior direction and the inlet / outlet closing position. It is possible to move between the position behind the entrance and the opening position (the position shown in FIG. 5B) that opens the entrance 522A.

The developing cartridge 52 has a spring 524 that urges the reception shutter 523 toward the reception closing position. The reception shutter 523 can be moved to the reception closing position by being urged by the spring 524. Further, the inlet / outlet shutter 523 can move to the inlet / outlet open position by moving backward against the urging force of the spring 524.

On the right side of the developing frame 521, a first protrusion 521B and a second protrusion 521C that engage with the lock member 70 (see FIG. 9) of the drum cartridge 51 are provided. On the left and right surfaces of the developing frame 521, a third protrusion 521D that engages with the pressing and fixing portion (see FIG. 9) of the drum cartridge 51 is provided.

When such a developing cartridge 52 is mounted on the drum cartridge, the developing roller 55 can supply toner to the photosensitive drum 54 and the first position (position shown in FIG. 14) which is a position where the developing cartridge 52 can be attached to and detached from the drum cartridge. It is possible to move to and from a second position (position shown in FIG. 13) supported by a suitable position.

[Drum cartridge]
<Drum frame>
As shown in FIGS. 6 to 10, the drum cartridge 51 has a drum frame 511 that rotatably supports the photosensitive drum 54. The photosensitive drum 54 has a drum main body 541, a drum shaft 542A protruding to the left from the drum main body 541, and a drum shaft 542B protruding to the right from the drum main body 541, and the drum shafts 542A and 542B are drums. It is supported by the frame 511. The drum shaft 542A is an example of one end of the photosensitive drum, and the drum shaft 542B is an example of the other end of the photosensitive drum.

The drum frame 511 has a first side frame 511A arranged on the left side, a second side frame 511B arranged on the right side, an upper frame 511C, and a front frame 511D.

The first side frame 511A extends in a direction orthogonal to the rotation axis of the photosensitive drum 54 and rotatably supports the drum shaft 542A. The first side frame 511A has a support hole 512A at the lower end that rotatably supports the drum shaft 542A.

The second side frame 511B extends in a direction orthogonal to the rotation axis of the photosensitive drum 54 and rotatably supports the drum shaft 542B. The second side frame 511B has a support hole 512B at the lower end that rotatably supports the drum shaft 542B.

The upper frame 511C is a frame that extends in the left-right direction and the front-rear direction and connects the upper end portion of the first side frame 511A and the upper end portion of the second side frame 511B. The front frame 511D extends in the left-right direction and the up-down direction to connect the front end portion of the first side frame 511A and the front end portion of the second side frame 511B, and as shown in FIG. 8, the front end portion of the upper frame 511C to the leg portion. It is a frame that extends to the front of 63.

The front frame 511D does not have to be connected to the front end portion of the first side frame 511A. Further, the front frame 511D may be composed of a plurality of frames extending in the left-right direction. The drum frame 511 can accommodate the developing cartridge 52 in a space surrounded by the first side frame 511A, the second side frame 511B, the upper frame 511C, the front frame 511D, and the photosensitive drum 54.

<Guide groove>
A guide groove 513A is formed on the inner side surface of the first side frame 511A in the left-right direction, and a guide groove 513B is formed on the inner side surface of the second side frame 511B in the left-right direction. The guide grooves 513A and 513B extend substantially in the vertical direction and are curved rearward from the upper side to the lower side. The guide grooves 513A and 513B are formed above the photosensitive drum 54.

The upper ends of the guide grooves 513A and 513B are open, and the roller shaft 55A of the developing roller 55 can be inserted into the guide grooves 513A and 513B from above. By inserting the roller shaft 55A into the guide grooves 513A and 513B, the developing cartridge 52 can be mounted on the drum cartridge 51.

<Residual toner transport unit>
The drum cartridge 51 has a residual toner transport section 61 that transports the residual toner collected from the photosensitive drum 54 by the drum cleaner 59 to the residual toner storage section 522 of the developing cartridge 52. The residual toner transfer unit 61 includes a vertical transfer case 611, a horizontal transfer case 612, a conveyor 613, a screw 614, a residual toner transfer shutter 615, a first contact piece 616, and a second contact piece 617. It has a spring 618.

The vertical transport case 611 is arranged from the lower end to the upper end of the left end of the drum cartridge 51. The horizontal transport case 612 is arranged at the left end and the upper end of the drum cartridge 51, and is connected to the vertical transport case 611. At the lower end of the lateral transport case 612, a residual toner discharge port 612A through which the residual toner can pass is formed.

The conveyor 613 is provided inside the vertical transport case 611, and the residual toner collected by the drum cleaner 59 located at the lower end of the vertical transport case 611 in the vertical direction can be transported to the upper end of the vertical transport case 611. It is configured. The screw 614 is provided inside the lateral transport case 612 in a posture in which the axial direction is the left-right direction. The screw 614 is configured to be able to convey the residual toner conveyed to the upper end of the vertical transfer case 611 by the conveyor 613 toward the residual toner discharge port 612A.

The residual toner transfer shutter 615 is a shutter capable of opening and closing the residual toner discharge port 612A. The residual toner transfer shutter 615 is formed of a substantially cylindrical member, and is ring-mounted on the outer periphery of the lateral transfer case 612. The residual toner transfer shutter 615 has a communication port 615A and is configured to be rotatable with respect to the lateral transfer case 612.

The residual toner transfer shutter 615 rotates with respect to the horizontal transfer case 612, so that the residual toner discharge port 612A and the communication port 615A communicate with each other to open the residual toner discharge port 612A, and the residual toner discharge port open position. It is possible to move between the discharge port closing position where the remaining toner discharge port 612A is closed without communicating between the discharge port 612A and the communication port 615A.

The residual toner transfer shutter 615 is urged by a spring 618 to the side where the residual toner transfer shutter 615 is located at the discharge port closing position. The first contact piece 616 is provided on the residual toner transfer shutter 615, and is configured to be rotatable integrally with the residual toner transfer shutter 615. The first contact piece 616 is configured to be able to come into contact with the developing cartridge 52.

In the residual toner transport unit 61, when the developing cartridge 52 mounted on the drum cartridge 51 is in the first position (position shown in FIG. 14), the first contact piece 616 does not come into contact with the developing cartridge 52. The residual toner transfer shutter 615 moves to the discharge port closing position by the urging force of the spring 618. On the other hand, when the developing cartridge 52 mounted on the drum cartridge 51 is in the second position (position shown in FIG. 13), the first contact piece 616 comes into contact with the developing cartridge 52, and the residual toner transfer shutter 615 is spring 618. It is located in the open position of the discharge port against the urging force of.

The second contact piece 617 is provided on the residual toner transfer shutter 615, and is configured to be rotatable integrally with the residual toner transfer shutter 615. The second contact piece 617 is configured to be able to contact the receiving shutter 523 of the developing cartridge 52.

<Lock member>
As shown in FIG. 9, the drum cartridge 51 has a lock position (position shown by a solid line in FIG. 9) that prevents the development cartridge 52 from rotating from the second position to the first position, and a second position of the development cartridge 52. It has a lock member 70 that can move from the unlocked position (the position indicated by the alternate long and short dash line in FIG. 9) that allows rotation from the first position to the first position.

The second side frame 511B of the drum cartridge 51 has a rotating shaft 514 extending in the left-right direction. The lock member 70 is rotatably supported by a rotating shaft 514 and has a lock claw 71 as an example of an engaging portion, an operating lever 72 as an example of an operating portion, and a pressing lever 73. There is. The lock claw 71, the operating lever 72, and the pressing lever 73 are configured to be integrally rotatable around the rotating shaft 514. The lock member 70 can move between the lock position and the unlock position by rotating around the rotation shaft 514.

The lock claw 71 can be engaged with the first protrusion 521B of the developing cartridge 52. The pressing lever 73 can come into contact with the second protrusion 521C of the developing cartridge 52. The drum cartridge 51 has a spring 74 that urges the lock member 70 from the unlocked position toward the locked position.

The second side frame 511B of the drum cartridge 51 has a stopper 515 that can come into contact with the lock member 70. The stopper 515 has a first contact surface 515A capable of contacting the lock claw 71 and a second contact surface 515B capable of contacting the pressing lever 73.

When the lock member 70 rotates toward the lock position side and reaches the lock position, the first contact surface 515A abuts on the lock claw 71 and regulates the lock member 70 from rotating further. The second contact surface 515B abuts on the pressing lever 73 when the lock member 70 rotates toward the unlock position side and reaches the unlock position, and regulates the lock member 70 from rotating further. .. As a result, the lock member 70 can be moved between the lock position and the unlock position.

When the lock member 70 is in the locked position, as shown in FIG. 11, the lock claw 71 and the first protrusion 521B are engaged with each other to prevent the developing cartridge 52 from moving from the second position to the first position. To. On the other hand, when the lock member 70 is in the unlocked position, as shown in FIG. 12, the engagement between the lock claw 71 and the first protrusion 521B is released, and the developing cartridge 52 moves from the second position to the first position. Is allowed to do.

The operation lever 72 is an operation member that operates the switching between the lock position and the unlock position of the lock member 70. When the operating lever 72 is not operated and no force is applied to the operating lever 72 in the rotational direction, the lock member 70 moves to the locked position by the urging force of the spring 74. Further, by operating the operation lever 72 of the lock member 70 in the lock position toward the unlock position side, the lock member 70 can move to the unlock position against the urging force of the spring 74. ..

By providing the lock member 70 in this way, it is possible to prevent the developing cartridge 52 from moving from the second position to the first position, and it is possible to prevent the developing cartridge 52 from being unintentionally disengaged from the drum cartridge 51. ..

<Legs>
The drum cartridge 51 has a protruding position protruding from the drum cartridge 51 (position shown by a two-dot chain line in FIGS. 8 to 10) and a storage position not protruding from the drum cartridge 51 (position shown by a solid line in FIGS. 8 to 10). It has legs 63 that can be moved between them. The leg portion 63 is urged from the storage position toward the protruding position by a spring 64 as an example of the urging member. The leg portion 63 moves to the storage position against the urging force of the spring 64 when the drum cartridge 51 is attached to the drawer 80, and the leg portion 63 of the spring 64 is removed from the housing 2 when the drum cartridge 51 is removed from the housing 2. It moves to the protruding position by the urging force.

As a result, when the drum cartridge 51 removed from the drawer 80 is placed on the work table, the drum cartridge 51 is stably supported by the legs 63.

<Pressing fixing part>
As shown in FIGS. 8 and 9, the drum cartridge 51 has a pressing fixing portion 65 that presses and fixes the developing cartridge 52 in the direction in which the developing roller 55 abuts on the photosensitive drum 54. As shown in FIG. 7, the pressing fixing portions 65 are provided on the left and right ends inside the front frame 511D.

The pressing fixing portion 65 has a lock arm 651 that is rotatably supported by the front frame 511D, and a spring 652 that urges the lock arm 651 in the front-down direction. The lock arm 651 has a claw on the side opposite to the spring 652 that can be engaged with the third protrusion 521D of the developing cartridge 52.

As shown in FIG. 11, in the developing frame 521, the third projection 521D is pressed and fixed by the pressing fixing portion 65, so that the developing roller 55 is movably fixed in the direction of pressure contact with the photosensitive drum 54. Therefore, the positional relationship between the developing roller 55 supported by the developing frame 521 and the photosensitive drum 54 supported by the drum frame 511 can be maintained at an appropriate positional relationship suitable for development. For example, even if the developing roller 55 is slightly deformed, the positional relationship between the developing roller 55 and the photosensitive drum 54 can be maintained.

As shown in FIGS. 7 to 9, a roller 66 is provided above the pressing and fixing portion 65 of the front frame 511D. The roller 66 has a rotation axis parallel to the roller shaft 55A of the developing roller 55. The roller 66 contacts the front surface of the developing frame 521 when the developing cartridge 52 is in the second position to support the developing frame 521, and reduces the load when the developing cartridge 52 is moved by the pressing fixing portion 65.

[Mounting the developing cartridge on the drum cartridge]
11 to 14 show a horizontal operation in which the process cartridge 50 removed from the drawer 80 is horizontally oriented while the process cartridge 50 is mounted on the drawer 80, and the front frame 511D of the drum frame 511 is facing downward. It shows the state of being placed on the table. At this time, the leg portion 63 is positioned at the protruding position due to the urging force of the spring 64. Therefore, the process cartridge 50 is stably supported on the work table by the front frame 511D of the drum frame 511 and the legs 63.

11 and 13 show a state in which the developing cartridge 52 is in the second position, FIG. 12 shows a state in which the developing cartridge 52 is in a position pushed up by the pressing lever 73, and FIG. 14 shows a state in which the developing cartridge 52 is in the second position. It shows the state of being in one position.

The developing cartridge 52 mounted on the drum cartridge 51 can rotate between the first position and the second position with the roller shaft 55A of the developing roller 55 supported by the guide groove 513A as the rotation axis. is there. Therefore, when the developing cartridge 52 rotates between the first position and the second position, the possibility that the developing roller 55 and the photosensitive drum 54 rub against each other and are damaged due to the rotation can be reduced.

The developing cartridge 52 at the second position is housed in a space surrounded by the first side frame 511A, the second side frame 511B, the upper frame 511C, and the front frame 511D of the drum frame 511. Then, when the developing cartridge 52 is rotated from the second position to the first position, the developing cartridge 52 rotates upward away from the front frame 511D. Therefore, it is possible to easily attach / detach the developing cartridge 52 with the process cartridge 50 placed on the work table with the front frame 511D facing down.

As shown in FIG. 11, the developing cartridge 52 at the second position is fixed to the drum cartridge 51 by the lock member 70 and the pressing fixing portion 65, and is connected to the residual toner conveying portion 61 as shown in FIG. .. As shown in FIG. 12, the developing cartridge 52 between the second position and the first position is pushed up by the lock member 70 and separated from the pressing fixing portion 65. As shown in FIG. 14, the developing cartridge 52 at the first position is separated from the residual toner conveying portion 61. The operation of each part when the developing cartridge 52 moves between the first position and the second position will be described below.

<Operation of lock member>
As shown in FIG. 11, with the process cartridge 50 placed on a horizontal surface, the operation lever 72 is located above the lock claw 71, and the lock member 70 in the lock position is locked by pushing down the operation lever 72. It can be moved to the release position. Since the operation lever 72 is simply pushed down, it is easy to unlock the lock member 70.

Then, in the process of moving the lock member 70 from the lock position to the unlock position, as shown in FIG. 12, the pressing lever 73 comes into contact with the second protrusion 521C and pushes up the second protrusion 521C upward. When the second protrusion 521C is pushed upward, the developing cartridge 52 at the second position rotates upward around the roller shaft 55A of the developing roller 55.

As shown in FIG. 14, the user can grasp the handle 521A that has moved upward and rotate the developing cartridge 52 further upward to the first position to separate the developing cartridge 52 from the drum cartridge 51. ..

Conversely, when moving the developing cartridge 52 in the first position to the second position, the user only has to push down the developing cartridge 52. As a result, the second protrusion 521C pushes down the pressing lever 73, the lock member 70 rotates from the unlocked position to the locked position, and the lock claw 71 engages with the first protrusion 521B.

<Operation of pressing fixing part>
As shown in FIG. 11, with the process cartridge 50 placed on a horizontal surface, the pressing fixing portion 65 presses and fixes the third protrusion 521D of the developing frame 521. When the operating lever 72 is pushed down and the developing cartridge 52 rotates upward from this state, the third protrusion 521D separates upward from the pressing fixing portion 65 against the fixing force of the pressing fixing portion 65.

On the contrary, when the developing cartridge 52 in the first position is moved to the second position, the developing cartridge 52 is pushed down by the user, and the pressing fixing portion 65 is pushed and engaged with the descending third protrusion 521D.

<Operation of inlet shutter and residual toner transfer shutter>
As shown in FIG. 14, when the developing cartridge 52 mounted on the drum cartridge 51 is in the first position, the receiving / receiving shutter 523 is moved to the receiving / receiving closing position by the urging force of the spring 524. Further, the first contact piece 616 is not in contact with the developing cartridge 52, and the residual toner transfer shutter 615 is moved to the discharge port closing position.

From this state, when the developing cartridge 52 is rotated to the second position with respect to the drum cartridge 51, as shown in FIG. 13, the second contact piece 617 comes into contact with the receiving / receiving shutter 523, and the receiving / receiving shutter 523 Is moved to the receiving port open position against the urging force of the spring 524. As a result, the receiving port 522A is opened.

Further, the first contact piece 616 comes into contact with the developing cartridge 52, the residual toner transfer shutter 615 is moved to the discharge port open position against the urging force of the urging member, and the residual toner discharge port 612A is opened. .. As a result, the residual toner discharge port 612A and the reception port 522A communicate with each other, and the residual toner conveyed to the position of the residual toner discharge port 612A is passed through the residual toner discharge port 612A and the reception port 522A to the residual toner storage unit 522. It is discharged inside.

On the contrary, when the developing cartridge 52 at the second position is rotated to the first position with respect to the drum cartridge 51, the second contact piece 617 is separated from the receiving / receiving shutter 523, and the receiving / receiving shutter 523 is spring 524. It moves to the reception entrance closing position by the urging force of the above, and the reception entrance 522A is closed. Further, the first contact piece 616 is separated from the developing cartridge 52, the residual toner transfer shutter 615 is moved to the discharge port closing position by the urging force of the spring 618, and the residual toner discharge port 612A is closed.

In the state of FIG. 13, the residual toner contained in the residual toner accommodating portion 522 accumulates in the lower portion of the residual toner accommodating portion 522 away from the receiving port 522A by gravity. Therefore, when the developing cartridge 52 is attached to and detached from the drum cartridge 51, the residual toner in the residual toner accommodating portion 522 is unlikely to spill from the receiving port 522A.

[Drawer]
The drawer 80 is provided along the front-rear direction between an inner position (position shown in FIG. 1) housed in the housing 2 and an outer position (position shown in FIG. 18) in which a part of the drawer 80 is exposed to the outside of the housing 2. It is configured to be movable. As shown in FIG. 1, when the drawer 80 is mounted on the drawer 80 and the drawer 80 is in the inner position, the process cartridge 50 is housed in the housing 2.

Further, as shown in FIG. 18, when the drawer 80 is in the outer position with the process cartridge 50 mounted on the drawer 80, at least a part of the process cartridge 50 is exposed to the outside of the housing 2. .. When the drawer 80 is in the outer position, it is exposed to the outside of the housing 2.

The process cartridge 50 is removable from the drawer 80. Four guide grooves 81A are formed in each of the side frames 81 of the drawer 80. The guide groove 81A extends substantially in the vertical direction and is curved rearward from the upper side to the lower side.

The upper end of the guide groove 81A is open at the upper end of the drawer 80, and the support holes 512A and 512B of the drum frame 511 can be inserted into the guide groove 81A from above. By inserting the support holes 512A and 512B into the guide groove 81A, the process cartridge 50 can be mounted on the drawer 80.

[Removal of process cartridge and development cartridge]
Here, as shown in FIG. 19, regarding the four process cartridges 50 mounted on the drawer 80, the process cartridge 50 located at the frontmost position in the front-rear direction is designated as the first process cartridge 50-1, and the first process cartridge 50- The process cartridge 50 located behind 1 is referred to as the second process cartridge 50-2, the process cartridge 50 located behind the second process cartridge 50-2 is referred to as the third process cartridge 50-3, and the third process cartridge 50- The process cartridge 50 located behind 3 is referred to as a fourth process cartridge 50-4.

The first process cartridge 50-1 has a first drum cartridge 51-1 and a first developing cartridge 52-1. The second process cartridge 50-2 has a second drum cartridge 51-2 and a second developing cartridge 52-2. The third process cartridge 50-3 has a third drum cartridge 51-3 and a third developing cartridge 52-3. The fourth process cartridge 50-4 has a fourth drum cartridge 51-4 and a fourth developing cartridge 52-4.

The first drum cartridge 51-1 has a first drum frame 511-1, a first photosensitive drum 54-1 and a first lock member 70-1. The second drum cartridge 51-2 has a second drum frame 511-2, a second photosensitive drum 54-2, and a second lock member 70-2. The third drum cartridge 51-3 has a third drum frame 511-3, a third photosensitive drum 54-3, and a third lock member 70-3. The fourth drum cartridge 51-4 has a fourth drum frame 511-4, a fourth photosensitive drum 54-4, and a fourth lock member 70-4.

The first lock member 70-1 has a first lock claw 71-1 and a first operating lever 72-1. The second lock member 70-2 has a second lock claw 71-2 and a second operating lever 72-2. The third lock member 70-3 has a third lock claw 71-3 and a first operating lever 72-3. The fourth lock member 70-4 has a fourth lock claw 71-4 and a first operating lever 72-4.

The first development cartridge 52-1 has a first development frame 521-1 and a first development roller 55-1, and the second development cartridge 52-2 has a second development frame 521-2 and a second development roller 55-2. The third development cartridge 52-3 has a third development frame 521-3 and a third development roller 55-3, and the fourth development cartridge 52-4 has a fourth development frame 521-4 and a fourth development. It has rollers 55-4.

The second process cartridge 50-2 is detachably attached to the drawer 80 and is arranged adjacent to the first process cartridge 50-1 attached to the drawer 80. The image forming apparatus 1 has a second process cartridge 50-2, a third process cartridge 50-3, and a fourth process cartridge 50-4 in addition to the first process cartridge 50-1, thereby producing a multicolor image. It is possible to form.

As shown in FIG. 18, in the image forming apparatus 1, the process cartridge 50 attached to the drawer 80 is detached from the drawer 80 in a state where the front cover 22 is opened and the drawer 80 is moved to the outer position. It is possible. At this time, the user can hold the handle 521A and separate the drum cartridge 51 equipped with the developing cartridge 52 from the drawer 80.

In such a configuration, as shown in FIG. 19, the first process cartridge 50-1 to which the first developing cartridge 52-1 is mounted and positioned at the second position and the second process cartridge 50-2 are drawn. It is assumed that the first developing cartridge 52-1 is moved from the second position (the position indicated by the solid line in FIG. 19) to the first position (the position indicated by the alternate long and short dash line in FIG. 19) while being mounted on the 80. To do. In this case, before the first development cartridge 52-1 reaches the first position, the first development cartridge 52-1 and the second drum frame 511-2 of the second process cartridge 50-2 interfere with each other for the first development. Cartridge 52-1 does not reach the first position.

Therefore, in the "method of replacing the developing cartridge with the process cartridge attached to the drawer", the first developing cartridge 52-1 cannot be replaced, thereby ensuring that the user "removes the process cartridge from the drawer". Then you can lead to "How to replace the developing cartridge". In other words, the user will not be confused as to which of "the method of replacing the developing cartridge with the process cartridge attached to the drawer" and "the method of removing the process cartridge from the drawer and then replacing the developing cartridge" is the correct operation. ..

Further, with the first process cartridge 50-1 and the second process cartridge 50-2 equipped with the first developing cartridge 52-1 mounted on the drawer 80, the first developing cartridge 52-1 is placed in the second position to the first position. The distance between the first process cartridge 50-1 and the second process cartridge 50-2 is so narrow that the first developing cartridge 52-1 and the second process cartridge 50-2 interfere with each other when the first developing cartridge 52-1 and the second process cartridge 50-2 interfere with each other. Therefore, the size of the entire image forming apparatus 1 is reduced.

The same applies to the relationship between the second process cartridge 50-2 and the third process cartridge 50-3, and the relationship between the third process cartridge 50-3 and the fourth process cartridge 50-4. Regarding the 4th process cartridge 50-4, when the 4th developing cartridge 52-4 is moved from the 2nd position to the 1st position, the 4th developing cartridge 52-4 is the first before reaching the 1st position. 4 The development cartridge 52-4 interferes with the drawer 80, and the fourth development cartridge 52-4 does not reach the first position.

Further, in FIG. 19, in the image forming apparatus 1, the drawer 80 is located at the outer position, the first process cartridge 50-1 and the second process cartridge 50-2 are supported by the drawer 80, and the first lock member 70-1 is locked. In position. In this state, the first operating lever 72-1 of the first lock member 70-1 protrudes rearward from the first drum cartridge 51-1, and the first process cartridge 50-1 and the second process in the front-rear direction. It is arranged at a position sandwiched between the cartridge 50-2 and the cartridge 50-2.

With this configuration, when the first process cartridge 50-1 is mounted on the drawer 80, it becomes difficult to operate the first operation lever 72-1, and the lock of the first lock member 70-1 is released. Can be suppressed.

Further, in the image forming apparatus 1 in the state of FIG. 19, the first operating lever 72-1 at the unlocked position (the position indicated by the alternate long and short dash line in FIG. 19) is in the locked position (shown by the solid line in FIG. 19). Position) is located above the first operating lever 72-1.

Further, in the image forming apparatus 1 shown in FIG. 19, the upper frame 511C of the first drum cartridge 51-1 covers at least a part of the upper surface of the first developing cartridge 52-1.

With this configuration, when the drawer 80 is in the outer position, at least a part of the upper surface of the first developing cartridge 52-1 is covered and hidden by the upper frame 511C of the first drum cartridge 51-1. It becomes difficult for the user to grasp the first development cartridge 52-1. As a result, the user can be more reliably guided to "a method of removing the process cartridge from the drawer and then replacing the developing cartridge".

By the way, in the image forming apparatus 1 shown in FIGS. 18 and 19, if the operation lever 72 is configured to be easy to operate, the drawer 80 is pushed downward as the user operates the operation lever 72. In some cases. In this case, when the drawer 80 is pushed downward, there is a problem that the entire image forming apparatus 1 tends to fall forward.

On the other hand, in the configuration of the present embodiment, the process cartridge 50 is pulled out upward and removed while the drawer 80 is in the outer position, and then the process cartridge 50 is placed alone on the work table and the operation lever 72 is operated to operate the drum. The cartridge 51 and the developing cartridge 52 are separated. Therefore, the drawer 80 is not pushed downward as the user operates the operation lever 72 while the drawer 80 is in the outer position. Therefore, there is an advantage that the entire image forming apparatus 1 is unlikely to tip over to the front side.

[Drum cartridge and drawer support structure]
As shown in FIG. 15, the housing 2 has a vertical frame 24 extending in the front-rear direction and the up-down direction. The vertical frame 24 is arranged at the left and right ends in the housing 2. As shown in FIGS. 15 to 18, the vertical frame 24 has a guide hole 24A. The guide hole 24A is formed in an elongated hole shape extending substantially in the front-rear direction, and is inclined upward from the rear to the front. The guide holes 24A are formed at two locations along the front-rear direction.

A pair of left and right drawer guides 85 are provided on the left and right inside of the vertical frame 24 in the housing 2. The drawer guide 85 is a rail member that extends in the front-rear direction. A side frame 81 of the drawer 80 is supported on the drawer guide 85 so as to be movable back and forth.

The drawer guide 85 has guide pins 85A that project to the left and right outwards. The guide pin 85A is provided corresponding to the guide hole 24A, and is slidably inserted into the guide hole 24A. The drawer guide 85 is supported by the vertical frame 24 by inserting the guide pin 85A into the guide hole 24A. The drawer guide 85 is configured to be movable in the front-rear direction and the up-down direction with respect to the vertical frame 24 within a range in which the guide pin 85A can slide in the guide hole 24A.

At the front end of the drawer guide 85, engagement pins 85B projecting to the left and right outward are formed. The front cover 22 of the housing 2 has a link arm 27. The link arm 27 is formed in an arc shape that curves rearward and downward from the front cover 22 in a state where the front cover 22 is in the closed position. The link arm 27 has an engagement hole 27A that can be engaged with the engagement pin 85B. The engagement hole 27A is formed in an arc shape that curves downward from the front to the rear in a state where the front cover 22 is in the closed position.

With such a configuration, the drawer 80 can move in the front-rear direction between the inner position (the position shown in FIG. 17) and the outer position (the position shown in FIG. 8). That is, the moving direction of the drawer 80 is the front-rear direction, the side of the drawer 80 at the outer position in the moving direction is the front, and the side of the drawer 80 at the inner position in the moving direction is the rear.

In the drawer guide 85, the positioning position where the process cartridge 50 is positioned with respect to the housing 2 (position shown in FIG. 16) and the positioning of the process cartridge 50 with respect to the housing 2 are released, and the drawer 80 can move in the front-rear direction. It is configured to be movable along the front-rear direction from the positioning release position (position shown in FIG. 17).

As shown in FIG. 16, when the front cover 22 of the housing 2 is closed, the drawer 80 is located at the inner position and the drawer guide 85 is located at the positioning position. When the drawer guide 85 is in the positioning position, the guide pin 85A is located at the rear end of the guide hole 24A. Therefore, the drawer guide 85 is located rearward and downward in the movable range.

The housing 2 has a horizontal frame 25 extending in the horizontal direction between the left and right vertical frames 24. The horizontal frame 25 is arranged below the drawer guide 85. A pair of left and right support plates 26, which are plate-like members extending in the front-rear direction, are erected on the horizontal frame 25. The support plate 26 is arranged on the left and right inside of the side frame 81 of the drawer 80.

As shown in FIGS. 15 and 16, a positioning recess 26A is formed at the upper end of the support plate 26 so as to align with the position of the process cartridge 50 in the front-rear direction. When the drawer guide 85 is in the positioning position, as shown in FIG. 15, the lower end of the first side frame 511A and the lower end of the second side frame 511B in the drum frame 511 of the drum cartridge 51 are supported from below by the positioning recess 26A. Has been done. By supporting the drum frame 511 by the positioning recess 26A, the drum cartridge 51 is positioned with respect to the housing 2.

The left and right support plates 26 are formed of sheet metal members made by pressing with the same mold, and are formed in the same shape. Therefore, when the drum cartridge 51 is positioned, the photosensitive drum 54 is accurately positioned.

As described above, the process cartridge 50 is positioned with respect to the housing 2 by being supported from below by the support plate 26 when the drawer guide 85 is in the positioning position.

When the front cover 22 of the housing 2 is opened from the state shown in FIG. 16, the link arm 27 moves forward and the engaging pin 85B engages with the rear end edge of the engaging hole 27A as shown in FIG. Then, the drawer guide 85 is pulled forward. The drawer guide 85 pulled forward moves forward and moves to the positioning release position.

In this case, as the drawer guide 85 moves forward, the guide pin 85A slides from the rear end to the front end of the guide hole 24A, so that the drawer guide 85 also moves upward.

As the drawer guide 85 moves forward and upward, the drawer 80 supported by the drawer guide 85 moves upward together with the process cartridge 50. As a result, the process cartridge 50 is separated upward from the support plate 26, and the state in which the process cartridge 50 is supported by the support plate 26 is released.

As the drawer guide 85 moves forward and upward, the drawer 80 moves straight up without moving forward. The process cartridge 50 supported by the drawer 80 also moves straight up. Therefore, the photosensitive drum 54 provided on the process cartridge 50 does not rub against the belt 31 in the front-rear direction, and the photosensitive drum 54 and the belt 31 are not easily scratched.

In this way, when the drawer guide 85 is in the positioning release position, the support state of the process cartridge 50 by the support plate 26 is released. As a result, the positioning of the process cartridge 50 with respect to the housing 2 is released, and the drawer 80 can move in the front-rear direction.

When the front cover 22 is opened and the drawer 80 can be moved in the front-rear direction, the user pulls the drawer 80 in the inner position forward to move the drawer 80 to the outer position as shown in FIG. It is possible.

When the drawer 80 is in the outer position, the drum cartridge 51 and the developing cartridge 52 of the process cartridge 50 exposed to the outside of the housing 2 can be attached to and detached from the drawer 80.

Further, the drawer 80 at the outer position can be moved to the inner position by pushing it backward. Further, when the front cover 22 is closed from the state where the front cover 22 is opened and the drawer guide 85 is moved to the positioning release position, the engaging pin 85B engages with the front end edge of the engaging hole 27A, and the drawer guide 85 is rearward. Is pressed against. The drawer guide 85 pressed backward moves to the rear and moves to the positioning position.

[Pressing member and interlocking mechanism]
As shown in FIGS. 15 to 18, the image forming apparatus 1 includes a pressing member 90 that presses the drum frame 511 and an interlocking mechanism 95 that moves the pressing member 90 in conjunction with the opening and closing of the front cover 22. ..

<Pressing member>
As shown in FIG. 16, one pressing member 90 is provided for each process cartridge. As shown in FIG. 15, the pressing member 90 is a hemispherical pressing portion 91 that abuts on the drum frame 511, a spring 92 whose lower end is fixed to the pressing portion 91, and a rod-shaped member that extends in the left-right direction and is a spring 92. It has a support member 93 that supports the upper end of the drum. The pressing portion 91 and the spring 92 are provided near both left and right ends of the support member 93.

The support member 93 is supported by the vertical frame 24 by inserting the left and right ends thereof into the guide holes 24B formed in the vertical frame 24 of the housing 2. As shown in FIG. 16, the guide hole 24B is formed in an elongated hole shape extending in the vertical direction. The guide hole 24B is arranged between the exposure unit 60 and the process cartridge 50 in the vertical direction. The guide holes 24B are arranged directly above the left and right end portions of the upper frame 511C of the drum frame 511 in the state of FIG. 16, and are formed at four locations along the front-rear direction.

By inserting the support member 93 into the guide hole 24B, the pressing member 90 is supported by the vertical frame 24. The pressing member 90 is configured to be movable in the vertical direction with respect to the vertical frame 24 within a range in which the supporting member 93 can slide in the guide hole 24B.

According to such a configuration, when the pressing member 90 is located at the upper end of the guide hole 24B, the pressing member 90 is located at a separated position (position shown in FIG. 17) away from the upper frame 511C. On the other hand, when the pressing member 90 is located at the lower end of the guide hole 24B, the pressing member 90 is located at a pressing position (position shown in FIG. 16) capable of pressing the upper frame 511C.

<Interlocking mechanism>
As shown in FIG. 16, the interlocking mechanism 95 is provided on the outside of the vertical frame 24, the first rack 96 provided on the front cover 22, the second rack 97 arranged along the outside of the vertical frame 24, and the second rack 97. It has a first pinion 98 that meshes with one rack 96, and a second pinion 99 that is provided outside the vertical frame 24 and meshes with the first pinion 98 and the second rack 97. The interlocking mechanism 95 is provided on both the left and right sides inside the image forming apparatus 1.

The first rack 96 is a flat plate member extending substantially rearward in an arc shape along the radius of gyration of the front cover 22 from the left and right ends on the inner surface of the front cover 22 in the state of FIG. The teeth 96A of the first rack 96 are formed along the upper surface outside the arc in the state of FIG.

The second rack 97 is a substantially rectangular flat plate member extending horizontally from the front end portion of the housing 2 to the vicinity of the rear end portion of the drawer 80 in the state of FIG. The teeth 97A of the second rack 97 are formed along the lower surface near the front end portion.

The second rack 97 has a guide hole 97B. The guide hole 97B is formed in an elongated hole shape extending substantially in the front-rear direction, and is inclined upward from the front to the rear. The vertical length of the guide hole 97B is equal to the vertical length of the guide hole 24B of the vertical frame 24. The guide holes 97B are formed at four locations along the front-rear direction corresponding to the pressing member 90.

The guide holes 97B are slidably inserted into the left and right ends of the support member 93 of the pressing member 90 on the left and right outer sides of the vertical frame 24. The second rack 97 is supported by the support member 93 by inserting the guide hole 97B into the support member 93. Therefore, when the second rack 97 moves in the front-rear direction, the support member 93 is guided along the guide hole 97B and moves in the vertical direction with respect to the vertical frame 24.

The first pinion 98 is provided at the outer front end of the vertical frame 24 and meshes with the front end of the teeth 96A of the first rack 96 in the state of FIG. The first pinion 98 is rotated by the movement of the first rack 96. That is, the first pinion 98 rotates in conjunction with the opening and closing of the front cover 22.

The second pinion 99 is provided at the outer front end portion of the vertical frame 24, and in the state of FIG. 16, the lower end portion thereof meshes with the first pinion 98, and the upper end portion thereof is the front end portion of the teeth 97A of the second rack 97. Is meshing with. The second pinion 99 is rotated by the rotation of the first pinion 98. Then, the rotation of the second pinion 99 causes the second rack 97 to move in the front-rear direction. That is, the second rack 97 moves in conjunction with the opening and closing of the front cover 22.

<Operation of pressing member and interlocking mechanism>
As shown in FIG. 16, the pressing member 90 is in a state where the drum cartridge 51 is mounted on the drawer 80, the developing cartridge 52 is mounted on the drum cartridge 51, the drawer 80 is in the inner position, and the front cover 22 is in the closed position. Presses the upper part of the upper frame 511C of the drum cartridge 51 downward.

Specifically, since the second rack 97 is located at the rearmost portion of the front-rear movement range, the support member 93 is located at the lower end portion of the guide hole 24B by being guided to the front end portion of the guide hole 97B. In this state, the support member 93 is restricted from moving in the vertical direction by the guide hole 97B. As a result, the pressing portion 91 comes into contact with the upper portion of the upper frame 511C, and the urging force of the spring 92 presses the upper frame 511C downward.

When the drum frame 511 is pressed downward, the lower end of the first side frame 511A and the lower end of the second side frame 511B of the drum frame 511 are positioned in the positioning recess 26A of the support plate 26 (see FIG. 15). .. By arranging the pressing member 90 above the upper frame 511C in this way, the drum frame 511 can be pressed to position the photosensitive drum 54. According to such a configuration, the pressing member 90 can be arranged in a space above the developing cartridge 52 where it is easy to arrange.

Further, in the state of FIG. 16, the pressing member 90 is located above the upper end portion of the residual toner conveying portion 61. Therefore, the pressing member 90 does not interfere with the residual toner conveying portion 61.

When the front cover 22 is moved toward the open position from the state shown in FIG. 16, the first rack 96 moves forward, so that the first pinion 98 and the second pinion 99 rotate, and the second rack 97 moves forward. Moving. As the second rack 97 moves forward, the support member 93 is guided from the front end portion to the rear end portion of the guide hole 97B and rises from the lower end portion to the upper end portion of the guide hole 24B.

Then, while the front cover 22 reaches the open position, the rear end portion of the first rack 96 is separated from the first pinion 98, the rotation of the first pinion 98 and the second pinion 99 is stopped, and the second pinion 99 is moved. The second rack 97 stops while being located at the rear end of the teeth 97A of the second rack 97. After that, as shown in FIG. 17, the front cover 22 reaches the open position.

When the second rack 97 is stopped, the rear end portion of the guide hole 97B reaches the support member 93, and the support member 93 rises to the upper end portion of the guide hole 24B. As a result, the pressing member 90 is located at a separated position (position shown in FIG. 17) separated from the upper frame 511C. When the front cover 22 moves from the open position to the closed position, the operation is the reverse of the above.

As described above, the interlocking mechanism 95 holds the pressing member 90 in a separated position away from the upper frame 511C when the front cover 22 is in the open position, while the pressing member 90 is in the closed position when the front cover 22 is in the closed position. Holds the upper frame 511C at a pressing position where it can be pressed. Therefore, by interlocking the movement of the pressing member 90 with the opening and closing of the front cover 22, it is possible to save the trouble of moving the pressing member 90.

1 Image forming device 2 Housing 2A Opening 22 Front cover (cover)
26 Support plate 50 Process cartridge 50-1 First process cartridge 50-2 Second process cartridge 51 Drum cartridge 51-1 First drum cartridge 52 Development cartridge 52-1 First development cartridge 54 Photosensitive drum 54-1 First photosensitive drum 55 Development roller 55-1 1st development roller 57 Toner accommodating part 59 Drum cleaner 61 Residual toner transport part 63 Leg part 64 Spring (biasing member)
65 Pressing fixing part 70 Lock member 70-1 First lock member 71 Lock claw (engagement part)
71-1 1st lock claw (1st engaging part)
72 Operation lever (operation unit)
72-1 1st operation lever (1st operation unit)
80 Drawer 90 Pressing member 95 Interlocking mechanism 511 Drum frame 511-1 1st drum frame 511A 1st side frame 511B 2nd side frame 511C Upper frame 511D Front frame 521 Development frame 521-1 1st development frame 522 Remaining toner storage unit

Claims (9)

A housing with an opening and
A drawer that is movable between an inner position that is housed in the housing and an outer position that is partially exposed to the outside of the housing through the opening.
A first process cartridge that can be attached to and detached from the drawer.
A first drum cartridge having a first photosensitive drum and a first drum frame that supports the first photosensitive drum, and
A first developing roller that supplies toner to the first photosensitive drum, a first developing frame that supports the first developing roller and can accommodate the toner, and is removable from the first drum cartridge. A first process cartridge comprising one developing cartridge,
A second process cartridge that can be attached to and detached from the drawer adjacent to the first process cartridge is provided.
When the first developing cartridge is mounted on the first drum cartridge, the first developing cartridge is in a position where it can be attached to and detached from the first drum cartridge, and the first developing roller puts toner on the first photosensitive drum. Movable to and from a second position supported in a supplyable position
With the first process cartridge mounted and positioned at the second position and the second process cartridge mounted on the drawer, the first developing cartridge is mounted from the second position to the first. When the first development cartridge is moved toward the position, the first development cartridge interferes with the second process cartridge before the first development cartridge reaches the first position, and the first development cartridge is the first. An image forming apparatus characterized in that it does not reach a position. The first developing cartridge rotates between the first position and the second position about the rotation axis of the first developing roller in a state of being mounted on the first drum cartridge. The image forming apparatus according to claim 1. The first drum cartridge has a lock position that prevents the first development cartridge from rotating from the second position to the first position, and a lock position that prevents the first development cartridge from rotating from the second position to the first position. The image forming apparatus according to claim 1 or 2, wherein the image forming apparatus has a first lock member that can move to and from an unlocked position that allows rotation. The first lock member has a first operating portion and a first engaging portion that engages with the first developing cartridge.
In a state where the drawer is in the outer position, the first process cartridge and the second process cartridge are supported by the drawer, and the first lock member is in the lock position, the first operation unit is the first. The image forming apparatus according to claim 3, wherein the image forming apparatus is arranged at a position sandwiched between the 1 process cartridge and the 2nd process cartridge. With the drawer in the outer position and the first process cartridge supported by the drawer, the first operating unit in the unlocked position is above the first operating unit in the locked position. The image forming apparatus according to claim 4, wherein the image forming apparatus is located in. The first drum frame has a first side frame and a second side frame.
In a state where the first developing cartridge is mounted on the first drum cartridge, the first developing cartridge has a first position and a second position between the first side frame and the second side frame. The image forming apparatus according to claim 4 or 5, wherein the image forming apparatus is rotatably supported between the two. The first drum frame has an upper frame that connects the first side frame and the second side frame.
The first developing cartridge is housed in a space sandwiched between the first photosensitive drum and the upper frame in a state of being mounted on the first drum cartridge and in the second position.
The first drum frame in a state where the drawer is in the outer position, the first process cartridge is supported by the drawer, and the first developing cartridge is mounted on the first drum cartridge and is in the second position. The image forming apparatus according to claim 6, wherein the upper frame covers at least a part of the upper surface of the first developing cartridge. The first drum frame has a front frame that connects the first side frame and the second side frame.
In a state where the first developing cartridge is mounted on the first drum cartridge and is in the second position, the first developing cartridge is placed in a space surrounded by the first side frame, the second side frame, and the front frame. Contained,
The first process cartridge is placed in a posture in which the front frame faces downward with the first development cartridge mounted on the first drum cartridge, and the first development cartridge is placed in the first position from the second position. The image forming apparatus according to claim 6, wherein the first developing cartridge rotates in a direction away from the front frame when the first developing cartridge is rotated to. When the first process cartridge is placed in a posture in which the front frame faces downward with the first developing cartridge mounted on the first drum cartridge, the first operating portion is moved from the first engaging portion. The image forming apparatus according to claim 8, wherein the first locking member moves from the locking position to the unlocking position when the first operating unit is pushed down.

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